But it can take years for people with MS to get a proper diagnosis. Now, research suggests that subtle symptoms of the disease may show up even 15 years before someone gets diagnosed with MS. He says he tends to discover these symptoms when he looks back at patient’s health history after an MS diagnosis. Doctors say it’s a stretch to suggest that you should assume you have MS if you’re only dealing with fatigue or mood changes. “Whenever you have a constellation of symptoms which are without a clear medical diagnosis, seeing a neurologist may be wise,” he says.